Body-mass-index (BMI) and alcohol consumption predict elevated serum alanine (ALT) and aspartate (AST) aminotransferase levels in young adults. It is unclear if alcohol intake and BMI and their joint association have a differential effect on ALT and AST levels in older adults.
To determine the association between alcohol, BMI, and their combined effect with serum ALT and AST in older community-dwelling adults in the United States.
Design and Setting
A cross-sectional, population-based study in older adults
(n=2364) from the Rancho Bernardo Study (54% women; mean age: 70 years, BMI: 25 kg/m2, alcohol users: 63%) who attended a research visit in 1984-87. BMI was recorded by a trained nurse and alcohol use ascertained by a validated questionnaire.
Multiply adjusted odds-ratio (OR) and 95% confidence intervals (CI) of elevated serum ALT and AST (defined as ≥ 30 U/L in men and ≥ 19 U/L in women) were calculated for alcohol and BMI separately and their joint exposure using multivariate logistic regression models adjusted for age, body mass index, total cholesterol, serum triglycerides, fasting plasma glucose, systolic blood pressure, and diabetes mellitus.
In multivariate-adjusted logistic regression models, obesity independently increased the odds of elevated ALT in this cohort of older men and women by 3.0 (95% CI, 1.7-5.3) and 1.8 (95%CI, 1.1-2.7), respectively. Joint effects of consuming > 3 alcoholic drinks/day and obesity raised the odds of elevated ALT by 8.9 (95%CI, 2.4-33.1) and AST by 21-fold (95%CI, 2.6-170.1), demonstrating synergism. Obese had higher odds of elevated ALT even at 0 ≤ 1 drink/day.
In older men and women, combination of obesity with alcohol is synergistic in increasing the risk of liver injury. Older obese should restrict their alcohol intake as the risk of liver injury is higher.